A method and system for extracting coal tar, semi-coke and magnetite from coal gangue.

Abstract

This invention discloses a method and system for extracting coal tar, semi-coke, and magnetite from coal gangue, belonging to the field of comprehensive utilization of coal gangue. The aim is to provide a method for extracting coal tar, semi-coke, and magnetite from coal gangue using a combined pyrolysis-magnetic separation-flotation technology. The specific steps are as follows: Step S1, the coal gangue is crushed and preheated to remove moisture; Step S2, the preheated coal gangue is pyrolyzed at 550-600℃ to obtain coal tar; Step S3, the pyrolyzed coal gangue undergoes a first dry high-intensity magnetic separation treatment, and the concentrate from the dry high-intensity magnetic separation is ground and then subjected to a second wet low-intensity magnetic separation to obtain magnetite; Step S4, the tailings from the dry high-intensity magnetic separation are ground and then subjected to flotation treatment to obtain semi-coke. This invention can extract coal tar, semi-coke, and magnetite from coal gangue, and is an effective method and system for the comprehensive utilization of coal gangue.

Description

Technical Field

[0001] This invention relates to a method and system for extracting coal tar, semi-coke and magnetite from coal gangue, belonging to the field of comprehensive utilization of coal gangue. Background Technology

[0002] The main methods of processing coal gangue are landfilling, underground backfilling, and manufacturing building materials. Landfilling not only occupies arable land but also pollutes the environment; while underground backfilling and manufacturing building materials cannot recycle the resource components contained in coal gangue.

[0003] Patent CN115539122A discloses a coal gangue underground filling system and method, which directly fills the mined coal gangue into the underground goaf. However, this method ignores the resource attributes of coal gangue, cannot process and utilize the coal gangue, and cannot be applied to existing stockpiled coal gangue.

[0004] Patent CN115368112A discloses a sintered coal gangue permeable brick and its preparation method. The brick is prepared by crushing, mixing, aging, pressing and molding and sintering raw materials such as coal gangue, clay, expanded polystyrene particles and lime powder. However, this method only sinters the coal gangue and does not extract and separate its resource components.

[0005] Patent CN101890395A discloses a method for extracting coal and pyrite from coal gangue. The method involves crushing and grinding the coal gangue into a slurry of -200 mesh, adding flotation reagents, and then performing flotation to obtain pyrite and coal. However, this method only extracts coal and pyrite. Summary of the Invention

[0006] The first aspect of this invention provides a process for extracting coal tar, semi-coke, and magnetite from coal gangue, the process flow diagram of which is shown below. Figure 1 As shown.

[0007] The main components of the coal gangue include 10–23.5 wt% volatile matter, 9–13.5 wt% fixed carbon and trace amounts of unavoidable organic impurities, and 43–79 wt% ash. The inorganic components of the coal gangue mainly include 40–58 wt% SiO2, 17–27 wt% Al2O3, 1.1–2 wt% Fe2O3, and small amounts of CaO, MgO, TiO2, etc. The mineral phase components mainly include kaolinite, quartz, pyrite, siderite, etc. The processing method includes the following steps: Step S1, crushing the coal gangue and preheating it to remove moisture; Step S2, pyrolyzing the preheated coal gangue at 550-600℃ to obtain coal tar; Step S3, subjecting the pyrolyzed coal gangue to a first dry high-intensity magnetic separation, grinding the concentrate from the dry high-intensity magnetic separation, and then subjecting it to a second wet low-intensity magnetic separation to obtain magnetite; Step S4, grinding the tailings from the dry high-intensity magnetic separation and then performing flotation to obtain semi-coke.

[0008] Further, in step S1, the coal gangue is crushed into particles with a particle size of 3 to 10 mm.

[0009] Furthermore, the preheating temperature is 200–250°C, and the preheating time is 30–60 min.

[0010] Further, in step S2, the pyrolysis furnace is either a closed pyrolysis furnace or a pyrolysis furnace with an external inert gas as a protective atmosphere, wherein the protective gas introduction rate is 40-50 ml / min. Preferably, a closed pyrolysis furnace is used.

[0011] Furthermore, in step S2, the pyrolysis temperature is 550–600℃, the heating regime during the pyrolysis process is as follows: the heating rate is 25℃ / min in the 0–250℃ stage, and 5–15℃ / min in the 250℃–pyrolysis temperature stage. The temperature is kept constant at the pyrolysis temperature for 60–120 min, and the furnace is cooled to room temperature after pyrolysis is completed.

[0012] Furthermore, in step S3, the first strong magnetic separation adopts dry magnetic separation with a magnetic field strength of 1 to 1.3T, and the particle size of the magnetic concentrate after grinding is -100 mesh. The second weak magnetic separation adopts wet magnetic separation with a magnetic field strength of 0.3 to 0.5T.

[0013] Furthermore, in step S4, the grinding particle size of the tailings from the strong magnetic separation is -200 mesh.

[0014] Further, in step S4, the flotation includes: mixing coal gangue with water to obtain a slurry with a solid content of 200-400 g / L, adding an inhibitor to the slurry, stirring for 1-2 minutes, adding a collector, stirring for another 1-2 minutes, and then adding a frother for flotation.

[0015] Furthermore, the inhibitor is selected from one or more of water glass and sodium hexametaphosphate, and the amount of inhibitor used is 0.2 to 0.4 kg per ton of coal gangue powder dry weight.

[0016] Furthermore, the frother is selected from one or more of 2-octanol, pine oil, or No. 4 flotation oil. The amount of frother used is 0.2 to 0.5 kg per ton of coal gangue powder (dry weight).

[0017] Furthermore, the collector is selected from one or more of kerosene, n-dodecane, or diesel oil; the amount of collector used is 0.6 to 1.5 kg per ton of coal gangue powder dry weight.

[0018] Further, the semi-coke is obtained by flotation for 8-10 minutes following a "rough-fine" process.

[0019] A second aspect of the present invention provides a system for extracting coal tar, semi-coke, and magnetite from coal gangue, which is implemented according to the above-described process, and the system layout diagram is shown below. Figure 2 As shown, it includes coarse crushing equipment

[100] , medium crushing equipment

[200] , and screening equipment.

[0020]

[300] Drying equipment

[400] , pyrolysis equipment

[500] , dewatering equipment

[600] , primary magnetic separation equipment

[700] , primary grinding equipment

[800] , secondary magnetic separation equipment

[900] , secondary grinding equipment

[1000] , and flotation equipment

[1100] . Among these, coarse crushing equipment

[100]

[0021] The intermediate crushing equipment

[200] is used to crush raw coal gangue ore, and the discharge port of the coarse crushing equipment

[100] is connected to the feed port of the intermediate crushing equipment

[200] . The screening equipment

[300] is used to classify the ore after closed-circuit crushing and is arranged in the intermediate crushing equipment.

[0022] Downstream of

[200] ; Drying equipment

[400] is used to preheat the graded small coal gangue pieces and is arranged in the screening equipment.

[0023] Downstream of

[300] ; pyrolysis equipment

[500] for pyrolysis extraction of coal tar from preheated coal gangue, arranged downstream of drying equipment

[400] ; dewatering equipment

[600] for dewatering coal tar, arranged on one side of pyrolysis equipment

[500] ; primary magnetic separator

[700] for dry high-intensity magnetic separation of small pieces of pyrolyzed coal gangue, arranged downstream of pyrolysis equipment

[500] ; first grinding equipment

[800] for grinding the primary magnetic separator

[700] ... The concentrate from the first grinding equipment

[800] is ground into a slurry and arranged on one side of the first-stage magnetic separator

[700] . The second-stage magnetic separator

[900] is used to perform wet weak magnetic separation on the slurry from the first grinding equipment

[800] and is arranged downstream of the first grinding equipment

[800] . The second grinding equipment

[1000] is used to grind the tailings from the first-stage magnetic separator

[700] into a slurry and is arranged on the other side of the first-stage magnetic separator

[700] . The flotation equipment

[1100] is used to process the tailings from the second grinding equipment

[1000] .

[0024] The slurry is subjected to flotation and is arranged downstream of the second grinding equipment

[1000] .

[0025] The coarse crushing equipment

[100] is a jaw crusher, the medium crushing equipment

[200] is a hammer crusher, the screening equipment

[300] is a double-layer banana screen, the drying equipment

[400] is a hot air dryer, the pyrolysis equipment

[500] is a pyrolysis furnace, the dewatering equipment

[600] is a coal tar dewatering centrifuge, the primary magnetic separation equipment

[700] is a dry electromagnetic magnetic separator, the secondary magnetic separation equipment

[900] is a wet electromagnetic slurry magnetic separator, the first grinding equipment

[800] and the second grinding equipment

[1000] are ball mills, and the flotation equipment

[1100] is a flotation machine. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart illustrating the method for extracting coal tar, semi-coke, and magnetite from coal gangue in an embodiment of the present invention.

[0027] Figure 2 This is a system layout diagram of the method of the present invention;

[0028] The attached diagrams are labeled as follows: 100 - coarse crushing equipment; 200 - medium crushing equipment; 300 - screening equipment; 400 - drying equipment; 500 - pyrolysis equipment; 600 - dewatering equipment; 700 - primary magnetic separation equipment; 800 - primary grinding equipment; 900 - secondary magnetic separation equipment; 1000 - secondary grinding equipment; 1100 - flotation equipment. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0030] As described in the background section of this application, there is a problem with the prior art in that it cannot effectively utilize coal gangue. To solve this problem, this application provides a method for processing coal gangue. The main components of coal gangue include 10-23.5 wt% volatile matter, 9-13.5 wt% fixed carbon and trace amounts of unavoidable organic impurities, and 43-79 wt% ash. The inorganic components in coal gangue mainly include 40-58 wt% SiO2, 17-27 wt% Al2O3, 1-5 wt% Fe2O3, and small amounts of CaO, MgO, TiO2, etc. The mineral phase components mainly include kaolinite, quartz, pyrite, siderite, etc.

[0031] The processing method includes the following steps: Step S1, crushing the coal gangue and preheating it to remove moisture; Step S2, pyrolyzing the preheated coal gangue at 550-600℃ to obtain coal tar; Step S3, subjecting the pyrolyzed coal gangue to a first dry high-intensity magnetic separation, grinding the concentrate from the dry high-intensity magnetic separation, and then subjecting it to a second wet low-intensity magnetic separation to obtain magnetite; Step S4, grinding the tailings from the dry high-intensity magnetic separation and then performing flotation to obtain semi-coke.

[0032] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0033] Example 1

[0034] The composition of coal gangue is shown in Table 1.

[0035] Table 1

[0036] Element <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[TiO2]]> CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> Loss on ignition Content (wt%) 49.48 25.00 1.42 0.65 0.54 0.17 0.31 0.22 19.89

[0037] Note: Loss on ignition includes fixed carbon, volatile matter, and moisture. These three indicators are listed separately in the industrial analysis of coal. However, when it comes to elemental content, loss on ignition is usually written.

[0038] 1 kg of raw coal gangue ore is crushed into small pieces of coal gangue, which are 5-10 mm in size.

[0039] (2) Place the above-mentioned small pieces of coal gangue into a hot air dryer for drying at a temperature of 250°C for 30 minutes.

[0040] (3) The dried small pieces of coal gangue were placed into a pyrolysis furnace for pyrolysis. The pyrolysis was carried out in a closed pyrolysis furnace at a temperature of 550°C for 1 hour. When the temperature reached 360°C, the liquid products were collected to obtain crude coal tar.

[0041] (4) The crude coal tar obtained after the above pyrolysis is put into a centrifuge for mechanical dehydration, and coal tar is obtained after dehydration.

[0042] (5) The small pieces of coal gangue after pyrolysis are placed into a dry electromagnetic separator for magnetic separation with a magnetic field strength of 1T.

[0043] (6) The concentrate obtained from the above magnetic separation is ground into a slurry of -100 mesh using a ball mill and then fed into a wet electromagnetic slurry magnetic separator for magnetic separation at a magnetic separation intensity of 0.5T to obtain magnetite. The composition of the obtained magnetite is shown in Table 2.

[0044] Table 2

[0045] Element <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[TiO2]]> CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> Loss on ignition Content (wt%) 43.21 13.93 30.93 0.65 3.35 1.75 1.01 0.31 4.41

[0046] (7) Grind the tailings after the above dry magnetic separation into a slurry of -200 mesh using a grinding mill;

[0047] (8) Add 0.2g of water glass, 0.6g of kerosene and 0.2g of terpineol to the above slurry in sequence, stir evenly, and the concentration of the flotation slurry is 200g / L.

[0048] (9) Flotation for 8 minutes using the “rough-fine” process to obtain semi-coke.

[0049] After processing using the above method, 1 kg of coal gangue can yield 2.3 g of coal tar, 21.6 g of magnetite (with an iron content of 30.93%), and 55 g of semi-coke powder.

[0050] Example 2

[0051] The difference from Example 1 is that the coal gangue is crushed into particles with a particle size of 3-5 mm.

[0052] After processing using the above method, 1 kg of coal gangue can yield 2.5 g of coal tar, 22.2 g of magnetite, with an iron content of 32.05% in the magnetite, and 58 g of semi-coke powder.

[0053] Example 3

[0054] The difference from Example 1 is that the coal gangue is crushed into particles with a size of 3-5 mm and the pyrolysis temperature is 600℃.

[0055] After processing using the above method, 1 kg of coal gangue can yield 2.75 g of coal tar, 22.8 g of magnetite (with an iron content of 32.25%), and 58.8 g of semi-coke powder.

[0056] Example 4

[0057] The difference from Example 1 is that the coal gangue is crushed into particles with a size of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours.

[0058] After processing using the above method, 1 kg of coal gangue can yield 3.1 g of coal tar, 23.3 g of magnetite, with an iron content of 32.37% in the magnetite, and 58.96 g of semi-coke powder.

[0059] Example 5

[0060] The difference from Example 1 is that the coal gangue is crushed into particles with a size of 3-5 mm, the pyrolysis temperature is 600℃, the pyrolysis time is 2 hours, and the intensity of wet magnetic separation is 0.3T.

[0061] After processing using the above method, 1 kg of coal gangue yields 3.1 g of coal tar, 20.7 g of magnetite (with an iron content of 33.26%), and 58.96 g of semi-coke powder.

[0062] Example 6

[0063] The difference from Example 1 is that the coal gangue is crushed into particles with a size of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours. The magnetic field strength of the dry magnetic separation is 1.3T, and the strength of the wet magnetic separation is 0.3T.

[0064] After processing using the above method, 1 kg of coal gangue can yield 3.1 g of coal tar, 21.7 g of magnetite, with an iron content of 32.78% in the magnetite, and 58.73 g of semi-coke powder.

[0065] Example 7

[0066] The difference from Example 1 is that the coal gangue is crushed to particles of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours. The magnetic field strength of the dry magnetic separation is 1.3 T, and the strength of the wet magnetic separation is 0.3 T. The slurry concentration is...

[0067] 300g / L.

[0068] After processing using the above method, 1 kg of coal gangue can yield 3.1 g of coal tar, 21.8 g of magnetite (with an iron content of 32.78%), and 62.4 g of semi-coke powder.

[0069] Example 8

[0070] The difference from Example 1 is that the coal gangue is crushed to particles of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours. The magnetic field strength of the dry magnetic separation is 1.3 T, and the strength of the wet magnetic separation is 0.3 T. The slurry concentration is...

[0071] 400g / L.

[0072] After processing using the above method, 1 kg of coal gangue can yield 3.1 g of coal tar, 21.7 g of magnetite (with an iron content of 32.78%), and 63.8 g of semi-coke powder.

[0073] Example 9

[0074] The difference from Example 1 is that the coal gangue is crushed to particles of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours. The magnetic field strength of the dry magnetic separation is 1.3 T, and the strength of the wet magnetic separation is 0.3 T. The slurry concentration is...

[0075] 400g / L, water glass 0.3g, kerosene 1g, terpineol 0.35g,

[0076] After processing using the above method, 1 kg of coal gangue can yield 3.1 g of coal tar, 21.5 g of magnetite (with an iron content of 32.78%), and 66.1 g of semi-coke powder.

[0077] Example 10

[0078] The difference from Example 1 is that the coal gangue is crushed to particles of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours. The magnetic field strength of the dry magnetic separation is 1.3 T, and the strength of the wet magnetic separation is 0.3 T. The slurry concentration is...

[0079] 400g / L, water glass 0.4g, kerosene 1.2g, terpineol 0.5g,

[0080] After processing using the above method, 1 kg of coal gangue can yield 3.0 g of coal tar, 21.4 g of magnetite, with an iron content of 32.78% in the magnetite, and 68.3 g of semi-coke powder.

[0081] Example 11

[0082] The difference from Example 1 is that the coal gangue is crushed to particles of 3-5 mm, the pyrolysis temperature is 600℃, and the pyrolysis time is 2 hours. The magnetic field strength of the dry magnetic separation is 1.3 T, and the strength of the wet magnetic separation is 0.3 T. The slurry concentration is...

[0083] 200g / L, water glass 0.2g, kerosene 1g, terpineol 0.5g,

[0084] After processing using the above method, 1 kg of coal gangue can yield 3.1 g of coal tar, 21.7 g of magnetite (with an iron content of 32.78%), and 65.6 g of semi-coke powder.

[0085] Example 12

[0086] The difference from Example 1 is that the pyrolysis furnace used is a pyrolysis furnace with an external nitrogen protective atmosphere.

[0087] After processing using the above method, 1 kg of coal gangue can yield 1.8 g of coal tar, 21.9 g of magnetite, with an iron content of 31.12% in the magnetite, and 58.2 g of semi-coke powder.

[0088] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of extracting coal tar, semicoke and magnetite from coal gangue, characterized by, The method comprises the following steps: Step S1, crushing the coal gangue raw ore, grading the crushed coal gangue according to the preset particle size requirement, and returning the coal gangue with a particle size of more than 10 mm for re-crushing; the small coal gangue with a particle size of 3 mm to 10 mm is taken as the screening product, and the screened coal gangue is preheated; Step S2, pyrolyzing the preheated coal gangue in a pyrolysis furnace, and dehydrating the pyrolyzed product to obtain coal tar; Step S3, performing first dry high-intensity magnetic separation on the pyrolyzed coal gangue, grinding the high-intensity magnetic separation concentrate, and performing second wet low-intensity magnetic separation on the ground concentrate to obtain magnetite; Step S4, grinding the tailings of the first dry high-intensity magnetic separation, and performing flotation on the ground tailings to obtain semi-coke.

2. The process for extracting coal tar, semicoke and magnetite from coal rejects as claimed in claim 1 wherein, In the step S1, the coal gangue is crushed to particles with a particle size of 3 mm to 10 mm, and the closed-circuit crushing is performed by first coarse crushing and then medium crushing; the medium crushing product is screened, and the ore with a particle size of more than 10 mm is returned to the two-stage closed-circuit crushing for re-crushing.

3. The method of extracting coal tar, semicoke and magnetite from coal refuse as claimed in claim 1, wherein, In the step S1, the crushed coal gangue is preheated in a hot air dryer, the preheating temperature is 200-250 DEG C, and the preheating time is 30-60 min.

4. The method of extracting coal tar, semicoke and magnetite from coal refuse according to claim 1, wherein, In the step S2, the preheated coal gangue is put into a pyrolysis furnace for pyrolysis, the pyrolysis furnace is a closed pyrolysis furnace or a pyrolysis furnace with an external inert gas as a protective atmosphere, and the protective gas is introduced at a rate of 40-50 ml / min.

5. The method of extracting coal tar, semicoke and magnetite from coal refuse according to claim 1, wherein, In the step S2, the preheated coal gangue is put into a pyrolysis furnace for pyrolysis, the pyrolysis temperature is 550-600 DEG C, the temperature rising system in the pyrolysis process is that the temperature rising rate is 25 DEG C / min in the 0-250 DEG C stage, the temperature rising rate is 5-15 DEG C / min in the 250 DEG C-pyrolysis temperature stage, the pyrolysis temperature is kept constant for 60-120 min, and the pyrolysis is completed and the furnace is cooled to room temperature.

6. The method of extracting coal tar, meta-coke and magnetite from coal refuse as claimed in claim 1 wherein, In the step S3, the first high-intensity magnetic separation is dry magnetic separation, the magnetic field strength is 1-1.3 T, the particle size of the ground high-intensity magnetic separation concentrate is-100 mesh, and the second low-intensity magnetic separation is wet magnetic separation, the magnetic field strength is 0.3-0.5 T.

7. The process for extracting coal tar, semicoke and magnetite from coal refuse as claimed in claim 1 wherein, In the step S4, the grinding particle size of the high-intensity magnetic separation tailings is-200 mesh.

8. The process for extracting coal tar, semicoke and magnetite from coal refuse as claimed in claim 1 wherein, In the step S4, the flotation comprises the following steps: mixing the coal gangue with water to obtain slurry with a solid content of 200-400 g / L, adding an inhibitor to the slurry, stirring for 1-2 min, adding a collector, stirring for 1-2 min, and then adding a frother for flotation.

9. The process for extracting coal tar, semicoke and magnetite from coal refuse as claimed in claim 1 wherein, In the step S4, the inhibitor is selected from one or more of water glass and sodium hexametaphosphate, the amount of the inhibitor is 0.2-0.4 kg per ton of dry coal gangue powder, the frother is selected from one or more of sec-octyl alcohol, pine oil or No. 4 flotation oil, the amount of the frother is 0.2-0.5 kg per ton of dry coal gangue powder, the collector is selected from one or more of kerosene, n-dodecane or diesel oil, the amount of the collector is 0.6-1.5 kg per ton of dry coal gangue powder, and the flotation is performed according to the "rough-precise" process for 8-10 min.

10. A system for extracting coal tar, semicoke and magnetite from coal refuse, characterized by The application relates to a coal gangue processing system, which comprises a coarse crushing device (100), a medium crushing device (200), a screening device (300), a drying device (400), a pyrolysis device (500), a dehydration device (600), a primary magnetic separation device (700), a first grinding device (800), a secondary magnetic separation device (900), a second grinding device (1000) and a flotation device (1100), wherein the coarse crushing device (100) and the medium crushing device (200) are used for crushing raw coal gangue, the discharge port of the coarse crushing device (100) is connected with the feeding port of the medium crushing device (200); the screening device (300) is used for grading the ore crushed in a closed circuit and is arranged downstream of the medium crushing device (200); the drying device (400) is used for preheating the small pieces of coal gangue after grading and is arranged downstream of the screening device (300); the pyrolysis device (500) is used for pyrolyzing the coal gangue after preheating to extract coal tar and is arranged downstream of the drying device (400); the dehydration device (600) is used for the dehydration treatment of the coal tar and is arranged on one side of the pyrolysis device (500); the primary magnetic separation device (700) is used for dry high-intensity magnetic separation of the small pieces of coal gangue after pyrolysis and is arranged downstream of the pyrolysis device (500); the first grinding device (800) is used for grinding the concentrate of the primary magnetic separation device (700) into ore slurry and is arranged on one side of the primary magnetic separation device (700); the secondary magnetic separation device (900) is used for wet low-intensity magnetic separation of the ore slurry of the first grinding device (800) and is arranged downstream of the first grinding device (800); the second grinding device (1000) is used for grinding the tailings of the primary magnetic separation device (700) into ore slurry and is arranged on the other side of the primary magnetic separation device (700); and the flotation device (1100) is used for flotation of the ore slurry of the second grinding device (1000) and is arranged downstream of the second grinding device (1000). The coarse crushing device (100) is a jaw crusher, the medium crushing device (200) is a hammer crusher, the screening device (300) is a double-layer banana screen, the drying device (400) is a hot air dryer, the pyrolysis device (500) is a pyrolysis furnace, the dehydration device (600) is a coal tar dehydration centrifuge, the primary magnetic separation device (700) is a dry electromagnetic magnetic separator, the secondary magnetic separation device (900) is a wet electromagnetic slurry magnetic separator, the first grinding device (800) and the second grinding device (1000) are ball mills, and the flotation device (1100) is a flotation machine.

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